PROPUTY O] PAO P M ORI1
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dISSN 0256-1859 Vol. 7, No. 4, 1986
Problems of Occupational Health in the Americas
In the Region of the Americas knowledge of the problems of occupational health is limited by significant restrictions in available information. There is no or-dered or complete information system on occupational morbidity' and mortality. Few countries have up-to-date information on occupational accidents and dis-eases, and in most the data refer to events that are no longer current. This situation is partly due to the fact that most of the working population is not protected by social security systems; broad labor sectors resort to other health services (official services of the minis-tries of health, private offices, healers, and others) where work-related diseases and accidents are not re-corded. When information is available, accidents con-stitute most of the health problems recorded by workers and this seriously hinders the diagnosis of other work-related diseases.
The lack of information on occupational diseases can be explained in terms of the following factors:
* Many physicians who work in the health services
'For the purposes of this article, occupational morbidity is understood to mean the range of acute and chronic illnesses that take place in the worker population during work performance, deriving from work, or owing to factors present in the workplace. This concept includes accidents at work, chronic diseases that occur in workers exposed to harmful factors, and accidents while commuting.
of specialized labor centers and as general practitioners are not acquainted with specific work pathology and interpret it as common pathology. Consequently, occu-pational diseases may not be diagnosed as such. This fact is related to a deficiency in occupational health teaching in medical schools.
* For the same reasons indicated, broad sectors of the worker population do not have access to occupa-tional health services, and when they are served by general services, labor pathology is registered as com-mon disease.
* Occupational diseases, unlike accidents, do not always violently interrupt the labor process; the worker who suffers from a morbid process caused by work usually continues his functions, although his capabilities are diminished. The onset of occupational diseases is usually slow and progressive and, since functional re-serves are potentially high, manifestations likely to be detected by the worker or health personnel appear only in the later stages, sometimes even after the worker has retired from his work place.
The situation described is aggravated because most countries do not have classification lists for occupa-tional diseases or, if they have them, they are very heterogeneous; moreover, compulsory mechanisms for
IN THIS ISSUE ...
· Problems of Occupational Health in the Americas · Acute Respiratory Infections in a Cohort of Malnourished
Children in Mexico City
* Preliminary Report on an Epidemic Outbreak of Active Rheumatic Disease in Chile
* Registration of Chronic Disease in Canada: An Overview * Epidemiological Activities in the Countries
reporting of occupational diseases generally do not exist, and the information collected is rarely analyzed.
Another element that restricts knowledge of the problem is the limited amount of research carried out in this field. There is a notable contrast between re-search on occupational health and that developed in other health fields. In general, research in the clinical area predominates to the detriment of epidemiological and social studies. Execution of this type of research, framed in the general and specific conditions of each country, should be the basic principle supporting occu-pational health actions.
In spite of the above, there are some demographic data that make it possible to examine the relative mag-nitude of the labor population in recent years, and its variations in accordance with the level of development of the countries of the Region. In the period between 1960 and 1981 the countries with high industrial and agricultural development showed the highest percent-ages of economically active population, as was the case of Argentina, Canada, the United States, Trinidad and Tobago, and Uruguay. On the other hand, in 1981
coun-tries with single-crop agricultural export economies, such as Haiti, Honduras, and Nicaragua, showed the lowest percentages of active population: 53% for the first and 50% for the last two. It is interesting to note the changes in the trends of these percentages between the years 1960 and 1981 (Table 1). While there were countries such as Colombia, Costa Rica, and Trinidad and Tobago where the working population increased by 10%, there were others, such as Cuba, Ecuador, El Salvador, and Nicaragua where it remained stable, and still others, such as Argentina and Haiti, where the work force suffered a significant relative reduction.
The population occupied in agricultural activities in 1980 ranged between 2 and 5% in the United States and Canada, respectively, and 74, 63, and 55% in Haiti, Honduras, and Guatemala, although all countries with high percentages of agricultural work force -in 1960 showed an appreciable decline in 1980. This situation appears to be related to the mechanization of agricul-ture and the trend of rural population migration to the cities. Technological changes in agriculture, such as the use of agricultural machinery and pesticides, have
Table 1. Percentage of the work force by economic activity in 24 countries of Latin America and the Caribbean.
Economically active Work force (%) Population population (%)
(in thousands) (15-64 years old) Agriculture Industry Trade
Country 1980 1960 1981 1960 1980 1960 1980 1960 1980
Argentina 27,064 64 63 20 13 36 28 44 59
Bolivia 5,600 55 53 61 50 18 24 21 26
Brazil 123,032 54 55 52 30 15 24 33 46
Canada 23,940 59 67 13 5 34 29 52 66
Chile 11,104 57 62 31 19 20 19 50 61
Colombia 27,090 50 60 51 26 19 21 29 53
Costa Rica 2,245 50 59 51 29 19 23 30 48
Cuba 9,833 61 61 39 23 22 31 39 46
Dominican Republic 5,431 49 53 67 49 12 18 21 33
Ecuador 8,354 52 52 57 52 19 17 23 31
El Salvador 4,813 52 52 62 50 17 22 21 27
Guatemala 7,260 51 54 67 55 14 21 19 25
Haiti 5,010 55 53 80 74 6 7 14 19
Honduras 3,691 52 50 70 63 11 15 19 23
Jamaica 2,192 54 54 39 21 25 25 36 53
Mexico 71,910 51 52 55 36 20 26 25 39
Nicaragua 2,703 50 50 62 43 16 20 22 37
Panama 1,840 52 56 51 27 14 18 35 55
Paraguay 3,070 51 53 56 44 19 20 25 36
Peru 17,780 52 54 52 39 20 18 28 43
TrinidadandTobago 1,140 53 63 22 10 34 39 44 51
United States of America 227,158 60 66 7 2 36 32 57 66
Uruguay 2,899 64 63 21 11 30 32 50 57
Venezuela 13,913 51 55 35 18 22 27 43 55
Sources: Pan American Health Organization. Health Conditions in the Americas 1977-1980. Scientific Publication 427. Washington, D.C., 1982, Annex 1-2, p. 169; World Bank. World Development Report 1983. Washington, D.C., 1983, Table 21. p. 188.
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had a significant impact on workers' health. Several studies carried out in Costa Rica, El Salvador,
Guate-S)
mala, Honduras, and Nicaragua recorded 19,330 cases
of intoxication related to agricultural use of insecticides between 1971 and 1976. Considering that these results represent only the most seriously ill patients who sought hospital care, it can be assumed that the total figures are considerably greater (1).The steady increase of the population occupied in trade is significantly related to the increase in unem-ployment and underemunem-ployment, which are the results of the current economic crisis and of the search for informal work opportunities in this area of activity. A large portion of the latter population lacks medical services and any type of occupational health protection.
In recent decades, a considerable number of agricul-tural workers has been migrating from the countryside to the city where it constitutes a poorly skilled work force exposed to new and adverse labor conditions. This marginal population of urban areas is also sub-jected to other consequences, such as the deterioration of food intake, environmental pollution, inadequate housing, precarious health conditions, and unemploy-ment. The latter currently constitutes one of the most important problems in the countries of the Region. Around 20% of the economically active population is
unemployed and, if underemployment is added to this,
the total would reach 40% of the work force in some countries. Occupational health actions have made few inroads in this field and it will be necessary to consider the different activities performed by this commonly named "informal sector," to determine its morbidity and mortality profiles and the role that occupational health should play in their control.One problem that stands out in many countries of Latin America and the Caribbean is that of the partici-pation of minors in the work force. It is known that minors between the ages of 5 and 14 make up 13% of the working population (2). Information on this subject is limited and the little data available do not reflect the magnitude of the child labor problem. Theoretical-ly, labor laws in most countries prohibit the employ-ment of minors, which means that in certain production centers child labor does not appear on official records. On the basis of studies carried out in some countries, it is estimated that in 1984 there were approximately 15 million children under 15 years of age working in Latin America (1). Official documents showed that in that same year, in 13 countries of Latin America and the Caribbean, the number of child workers between _l10 and 14 years of age came close to four million
(Table 2). This critical situation is all the more compli-cated since these children are usually not protected by any occupational health program or, worse still, by any type of health service.
Table 2. Child workers: economically active population between 10 and 14 years of ageain some countries of
the Region of the Americas.
Child workers
Country (Year) Total (%)
Argentina(1983) 198,034 8.1
Bolivia(1976) 71,636 31.1
Brazil(1980) 1,922,218 14.2
Costa Rica (1983) 19,859 13.7
Ecuador(1982) 64,957 6.3
El Salvador (1980) 85,727 13.6
Guatemala(1981) 78,878 10.4
Haiti (1982) 138,823 24.0
Honduras(1983) 78,755 14.8
Mexico(1980) 1,121,816 12.1
Panama (1980) 9,572 4.2
Paraguay (1982) 45,140 11.8
Peru(1981) 124,231 5.7
Subtotal, 13 countries 3,959,646
Colombiab 3,000,000 11.4
Total 6,959,646
aAdapted from Yearbook of Labor Statistics, International Labor Organi-zation, 1984.
bData on Colombia estimated by the Ministry of Labor and Social Secu-rity (information for 1979).
Another element to be considered is the quantity and quality of occupational health services. In the Re-gion there are various academic and operational organi-zations engaged in services research and training of human resources in occupational health; among them, the institutes of social security, secretariats or minis-tries of health and labor, universities and institutes, and also the occupational health services of corpora-tions. In most cases, social security, as the institution responsible for protecting the worker population, has attained the greatest degree of development in occupa-tional health programs. Unfortunately, social security coverage in some countries does not even amount to 10% of the total labor population, and the great major-ity remains completely unprotected.
Universities have an important role to play in the training of professionals through education and research activities on occupational health. However, there is such a broad range of educational systems in the differ-ent countries, that some have programs at the under-graduate, under-graduate, and continuing education levels, while others do not include occupational health con-tents even in the undergraduate curriculum of the
med-ical schools.
Fundamental changes in morbidity and mortality profiles have emerged in most countries. While infec-tious diseases have shown a declining trend, accidents and work-related diseases have been increasing. This is reflected in the death rate due to traffic accidents, inasmuch as many of them are work-related. Vene-zuela, Mexico and Panama had the highest rates in 1980 with 37.4, 26.8 and 20.0 deaths per 100,000 population, respectively (3).
A significant number of traffic accidents occur dur-ing travel to and from work centers, adddur-ing further complications for the worker population that is suffer-ing from the impact of new livsuffer-ing conditions in large cities. In Colombia, for example, morbidity rates due to accidents for the period between 1977 and 1980 were higher in men than in women, this difference being more pronounced in the group between the ages of 15 and 44 years, which "could be attributed to the greater risk deriving from work, since 40.0% of the accidents are related to labor activity" (4).
A study carried out in Mexico analyzed the hetero-geneity of industrial labor processes as reflected in the various patterns of physical deterioration among work-ers. The authors identified three groups: the first, rep-resenting 12% of the workers, engages in simple man-ufacturing processes characterized by rudimentary technology, considerable physical effort performed during a long workday, and wages that are below the average industrial wage. The typical pattern of deterio-ration in this group is expressed in infectious-nutri-tional and musculoskeletal pathology. The second group includes 30% of the workers and it labors in machine processes characterized by a growing frag-mentation of tasks which can reach the extreme of comprising only a few movements performed in less than 15 seconds. These workers' deterioration pattern is expressed in a growing number of accidents, together with psychic, psychosomatic, and osteoneuromuscular pathology. The last group, which represents 55% of industrial workers, performs its functions in discrete automatic processes or continuous flow processes, which for the most part are not very complex in
technol-ogy or in the number of phases involved. In this group deterioration is manifested by diseases derived from prolonged psychic tension, serious accidents, and
malignant tumors (5).
Another study, also carried out in Mexico, was cen-tered on electricians who work with high-voltage cur-rent. It showed that this group of workers not only suffers a higher frequency of accidents but also a number of diseases that according to common medical interpretation do not appear to be work-related. Thus, hypertension and diabetes rates were four times greater than those of the control group; those for ischaemic heart diseases, six times greater; and those for peptic ulcer, eleven times greater. Morbidity excess was also expressed in a reduced survival rate, since after 10 years of retirement only 61.6% of those exposed to high-voltage electricity were still alive as opposed to 93.4% of the control group (5).
The International Labor Organization points out that in 1984, 6,843 fatal cases of work-related accidents were recorded in the Region. This figure seems unreal-istic when compared to the figures provided by the countries. Brazil alone, with a worker population of 25 million, notified 1,117,832 work-related accidents in 1982 with death rates reaching 18 per 100,000 popu-lation. In regard to morbidity, WHO studies that in-clude other countries such as Bolivia, Chile, Colombia, Ecuador, and Peru point out that the annual incidence of work-related accidents affects between 21 and 34% of the active population.
With work diseases the situation is more critical, since existing information is very limited. While acci-dents account for more than 90% of the total morbid processes officially recorded as work-related, work dis-eases recorded in some countries do not reach 1%.
In a survey carried out in 1984 by the Pan American Health Organization on occupational diseases in 12 countries of Latin America and the Caribbean, it was found that 25% of work pathology is due to lead poison-ing, pesticides, and alcohol; 24% to respiratory dis-eases, which include silicosis, byssinosis, and asthma; 20% to occupational dermopathies; 14% to hypoacusis and deafness, and 17% to diseases of the musculoskeletal system, and infectious and mental diseases. Most of this pathology was produced in the mining industry. The foregoing illustrates the need for occupational pathology, and especially toxicology, to be given spe-cial attention within the epidemiological surveillance of worker's health.
From what has been stated it may be derived that knowledge of the type and magnitude of health
lems related to work is incomplete and that there is an urgent need to develop and expand occupational health programs. However, this will only be feasible after adequate knowledge of the problems involved and of their determining factors is obtained. For this reason it is essential to organize information and epidemiolog-ical surveillance systems, preferably under common guidelines, in order to determine with firmer technical bases the true extent of biological and social damages, and the current effectiveness and efficiency of existing programs.
(Source: Workers' Health Program and Health Situation and Trend Assessment Program, PAHO.)
References
(1) Pan American Health Organization. Enfermedades ocupa-cionales. Guía para su diagnóstico. Scientific Publication 480. Washington, D.C., 1986.
(2) Pan American Health Organization. Health Conditions in the Americas, 1981-1984. Scientific Publication 500. Washington, D.C., 1986.
(3) Pan American Health Organization. Traffic Accidents in the Americas. Epidemiological Bulletin 5(2):1-4, 1984.
(4) Colombia. Ministerio de Salud. Población y morbilidad general. Morbilidad sentida 1977-1980. Bogotá, 1983.
(5) Laurell, A. C. Epidemiología, proceso colectivo de salud y enfermedad. Información Científica y Técnica (México) 7(103), 1985.
Acute Respiratory Infections in a Cohort of
Malnourished Children in Mexico City
Introduction
Acute respiratory infections (ARI), along with diarrheal diseases, are the most common causes of morbidity and mortality among children in developing countries. It is estimated that each year there are 2.2 million ARI-associated children deaths (1). The burden imposed by these infections on health services is con-siderable; in many clinics, they account for about one quarter of all consultations. Besides, they have other important consequences; one to two weeks of school per child per year may be lost because of ARI (2).
In spite of the excessive mortality and morbidity rates due to ARI, little is known about associated risk factors. Malnutrition is said to increase children's risk of contracting ARI (3) but this claim has not been clearly substantiated. It is, however, associated with increased mortality by that cause (1). In Mexico, for instance, childhood mortality due to ARI is about 30 times higher than in the United States and Canada (2),
and malnutrition is often given as the underlying cause (4). Complications of ARI have been found significant-ly more frequentsignificant-ly in malnourished children (5).
Two studies provide information about the occurrence of ARI in malnourished children. A longitudinal study * by James (5) concluded that the attack rate was the
same for malnourished and normal-weight children, but that the average duration was significantly longer for the former. This study evaluated nutritional status sev-eral times during the follow-up period but it was as-sumed to remain constant at the level assessed at entry. In addition, duration was defined as the sum of all days ill during the year, without controlling for number of episodes. A cross-sectional study by Wray (6) found the prevalence of ARI to be similar in normal and malnourished children. However, as in most cross-sec-tional studies, the direction of causality could not have been established even if an association had been found.
The objective of the present longitudinal study was to examine the association between nutritional status and the incidence and duration of ARI. The results indicate that nutritional status, defined in anthropometric terms, was not a predisposing factor for increased inci-dence or prolonged duration of ARI in this population.
Methods
This study was based at the Center for Primary Health Care Studies (CPHCS), a joint venture of the Ministry of Health and the National Autonomous Uni-versity of Mexico. The Center is located in Tlalpan, a district in the southern part of Mexico City, and
